Locator for machine tools,especially for punch presses



United States Patent LOCATOR FOR MACHINE TOOLS, ESPECIALLY FOR PUNCH PRESSES 10 Claims, 4 Drawing Figs.

11.8. 83/571, 83/628 Int. Cl B26d 7/00 Field ofSearch 83/571, 572, 573, 628

Primary ExaminerWilliam S. Lawson Attorney-Walter Becker ABSTRACT: A device for use in effecting the relative location of the work and tool in a machine tool, such as a punch press, in which a reciprocable slide carries the tool and a push rod abuts the slide on the side opposite the tool and embraces an eccentric which transmits power to the slide via the push rod. The device includes clutch elements on the slide and push rod which engage when the push rod abuts the slide but which can be disengaged when the slide is in retracted position to permit the slide to be advanced to the work, whereupon the work and the tool on the slide can be adjusted relatively to the desired position.

PATENTEU Dec] 5 mm SHEET 1 BF 2 )rmer 7A,

The present invention relates to a locating device for machine tools, especially punch presses, with a:device which is adapted during the locating operation to lower the punch car riage against the thrust of a spring or the like, said carriage being adapted to be disengaged from its driving rod. When it is desired to withdraw the carriage from its punching position, the carriage may again be coupled to the driving rod.

While the invention will be describedin connection with a punch press, it should be noted that the invention may be used in the same or a modified manner with other machine tools, such as shears and release mechanisms.

A locating device for punch presses has become known in which the punch carriage is connected to the driving rod through the intervention of a plate whichfis pivotally connected to said driving rod 'andcarriesfan eccentric. Another heretofore known locating device employsxa locating lever which is pivotally connected to the punch press housing and can be pivoted against the thrust of a spring, said locating lever being adapted by means of a disengaging pin engaging the punch carriage to disengage the coupling between the driving lever and the punch carriage.

With these heretofore known devices it is necessary to make the individual elements involved in the transfer of forces relatively strong and heavy. Frequently, a greater number of individual elements is necessary which ares'ubject to disorders and have to be replaced when worn out. With the above mentioned second heretofore known device it is furthermore necessary for uncoupling and locating purposes, to subject the actuating lever in the lever plane to a pivotal movement and to turn the lever perpendicularly to said plane. This is rather awkwardbecause the operator is close to thepunch press and has to pivot the engaging device with his arms stretched out 'high and then has to pull down the engaging device vertically.

the stock keeping-will be reduced to a minimum.

It is a still further object of this invention to' provide a locating device which w,ill.be sensitive in operation and can be produced at low cost while the servicing and the uncoupling of the carriage from the driving rod as well as'the locating can be effected by means of an actuating leverto be pivoted in one direction.

These and other objects and advantages of the invention will appear more clearly from the following vspecification in connection with the accompanying drawing, in which:

FIG. I diagrammatically shows a locatingd'evice according to the present invention. 7

FIG. 2 shows a slight modification of-a-portion of FIG. 1.

FIG. 3 shows the lever 20 of FIGrlon a somewhat larger scale and in a slightly different position: 7

FIG. 4 illustrates a slight modification of the arrangement of FIG. 3. t a

The locating device according to the present invention is characterized primarily in that the coupling can be disengaged by means of a stud, pivot, or piston or the like adapted to lower the carriage for the locating operation said coupling extending into the rectilinear path of movement of the pivot or piston.

According to a practical embodiment of the present invention, the driving rod is provided with a disengageable pawl which, for purposes of coupling the driving rod to the carriage, extends behind a nose or the like of the carriage. The pawl is provided with a sliding block or the like which engages the oblong hole of a pivotable angle lever against which rests the piston of a stationary pressure 'fluid cylinder'in such a way that when the piston moves outwardly, the angle lever will first be pivoted and subsequently the carriage will be lowered.

The angle lever may have two angle legs of different length and may be journaled on the shorter one of the two legs against which rests the pressure fluid piston. For purposes of limiting the pivot movement of the angle lever when the latter is subjected to the action of the pressure fluid piston, the car riage may be provided with a pivot or stud.

The angle lever may be under the influence of a spring which has the tendency to move the angle lever into a position in which the pawl is returned into its coupling position.

According to a further feature of the invention, the carriage may, by means of two lateral springs, preferably tension springs, be pulled in the direction toward the driving rod.

The pressure fluid cylinder may be actuated by means of a manual lever which can be moved in one pivotal direction only. The manual lever has a head provided with the release pivot or bolt for the punching operation.

Referring now to the drawing in detail, the punch press frame 1 has two guiding paths 2, 3 for the punch press carriage 4. Carriage 4 is provided with a round recess 5 engaged by the correspondingly designed part 6 of the driving rod 7. Driving rod 7 is moved by the eccentric 8 in such a way that the carriage, when the eccentric turns, carries out an upward and downward movement within the guiding means 2, 3 and the sidewalls of the punch frame 1.

The two guiding means 2, 3 are provided with longitudinal slots 9 through which extend studs or pivots 10 connected to the carriage 4. The free ends of said studs 10 are each engaged by a spring 11 the upper end 11a of which is respectively hooked to a stud 12 in the punch frame. The springs 11 urge the carriage 4 into engagement with the .driving rod 7.

Carriage 4carries a rail 13 the bottom side of which forms a nose 14 and has an incline 15. A pawl 16 cooperates with the nose 14 and the incline l5. Pawl 16 is pivotally journaled on part 6 of the driving rod 7 and is adapted to have its hookshaped end 17 engage the nose 14 from below as shown in full lines in the drawing. However, the pawl 16 may also slide on the incline 15 by means of its bent section and may in this way be caused to tilt.

Pawl 16 has a bolt or stud 18 which engages an oblong hole .18 of an angle lever 20. The leg 21 of said angle lever 20 is longer than the leg 22 while being opposite the carriage 4 under the influence of a spring 21a. The leg 21 has an oblong hole 19 extending in its longitudinaldirection. The leg 22 is rotatably journaled on pivot 23. The upper side of the shorter leg 22 is engaged by the piston 24 Ma fluid pressure cylinder 25 in such a way that when the piston 24 of the pressure fluid cylinder 25 moves downwardly, said cylinder 25 being stationarily mounted on the press frame, the angle lever 21, 22 will be pivoted against the thrust of spring 21a until it hits the abutment or stud 20. In this position, pawl 16 is likewise tilted from its illustrated coupling position while releasing nose 14. To the extent to which the piston 24 becomes effective further, the carriage 4 will, against the thrust of springs 11, be so depressed that the punching tool S, is lowered onto the material G to be punched.

For purposes of actuating the piston 24 in the stationary cylinder 25, there is employed an emitter cylinder 26 which is connected to the cylinder 25 through a conduit 27 and which is adapted to be actuated by a lever 29 through the linkage system 28. When pivoting this lever downwardly in the direction of the arrow K, the cylinder 25 is actuated while the lowering of the carriage 4 may be effected in a fine manner. When the dead center of the tool S, rests on the indicated center of the punch hole, pressure is exerted upon the bolt or stud 30 at the head of the manual lever 29 and the punching operation is initiated by adjusting the bolt or stud. Thus the eccentric 8 is rotated and the driving rod 7 moves downwardly. In the course of this movement, the driving rod 7 will, by means of its part 6,'engage the carriage 4. and press the same from its locating position through the material to be punched while the pawl 16, by means of its hook-shaped part 17, again catches below the nose 14 of the strip 13. This is effected by pivoting the angle lever 20, 22 by means of the spring 210 while the piston 24 is at a standstill and the carriage 4 has been moved downwardly so that the driving rod 7 and the carriage 4 are again coupled to each other. The bolt or stud 30 is displaceable in the direction of the arrow S. When the driving rod 7, following the punching operation, returns to its full line starting position, the pawl 16 carries along the carriage to the said position even if the tool S, is first firmly clamped in the material G to be punched.

It will be appreciated that when the part 6 moves downwardly in view of the rotation of the eccentric 8, part 6 engages carriage 4 which occupies its locating or searching position. Thus part 6 and carriage 4 are clutched to each other. it is to be noted that the carriage 4 is not retracted by springs 11, but after being clutched to part 6 is retracted by the latter. Springs 11 prevent carriage 4 from dropping when the carriage is not clutched to push rod or part 6.

' 'It is, of course, to be understood that the present invention is, by no means, limited to the particular construction shown in the drawing but also comprises any modifications within the scope of the appended claims.

We claim:

1, in a locating device for a punch press, said punch press having a frame with a work station therein, a slide guided in the frame for movement toward and away from said work station, an eccentric rotatable in the frame on the other side of said slide from said work station and a push rod having one end embracing said eccentric and its other end adapted for abutting said slide to drive the slide toward the work station when the eccentric rotates, interengageable elements of a clutch carried by said push rod and said slide and engageable when said other end of said push rod abuts said slide to couple the slide to the push rod and clutch actuating means selectively operable when said slide is in retracted position to disengage the elements of said clutch to release said slide from the push rod to permit the slide to be advanced toward the work station for the alignment of a tool carried by the slide with work in said work station.

2. A locating device according to claim 1, in which said slide is positioned vertically over said work station and is vertically reciprocable in the frame for working and retraction strokes.

3. A locating device according to claim 2, in which said clutch elements comprise a pawl pivotally connected to the said other end of said push rod and a pawl engaging element carried by said slide.

4. A locating device according to claim 3, in which said pawl depends substantially vertically from its pivotal connection with said other end of said push rod and has an upwardly facing shoulder on one lateral side, said pawl engaging element on said slide having a downwardly engaging shoulder engageable with the shoulder on said pawl when said other end of said push rod abuts said slide, said clutch actuating means including a lever pivotally mounted on said slide and slidably engaging said pawl and tiltable to move the pawl into pawl element disengaging position and a fluid actuated means in said frame selectively actuatable for moving said lever in a direction to disengage said pawl from said pawl engaging element.

5. A locating device according to claim 4, in which said lever is an angle lever and moves into position for actuation by said fluid operable means only when said slide is in retracted position, said fluid operable means comprising fluid operated piston-cylinder means adapted for abutting engagement with said lever.

6. A locating device according to claim 4, in which said lever is slotted and said pawl has a stud thereon engaging said slot and spring means is provided biasing said lever direction to cause said pawl to engage said pawl engaging element.

7. A locating device according to claim 6, in which said lever has a longer substantially vertical leg in which said slot is vertical] disposed to permit movement of the slide in the frame w en uncoupled from said push rod without disengaging said lever from the stud on the pawl, said lever having a shorter substantially horizontal leg at the lower end pivoted near its outer end to said slide, said piston-cylinder means being positioned in said frame vertically over said shorter leg in the path of movement thereof and operable upon actuation when the slide is in retracted position to move said leveragainst the bias of said spring means.

8. A locating device according to claim 2, which includes counterbalancing springs connected between said slide and said frame and biasing said slide toward said push rod while permitting the slide to be advanced from retracted position toward said work station when said clutch elements are disengaged.

9. A locating device according to claim 4, which includes a hand lever pivotally mounted on said frame and operatively connected to said fluid operable piston-cylinder means for selectively manually operating said fluid operable pistoncylinder means.

10. A locating device according to claim 9, in which said hand lever includes an element thereon actuatable for initiating rotating movement of said eccentric for a working operation. 

